These studies will explore treatment strategies for chronic lyme disease and will be conducted at two centers, New England Medical Center/Tufts University School of Medicine and Westchester County Medical Center affiliated with New York Medical College. The coordinating center, and the central laboratory facility will be at New England Medical Center. Investigators will perform an initial assessment of each patient for collection of demographic data, a history of exposure to ticks in geographic regions with endemic B. burgdorferi infection.